This invention relates to a hanger for use in conjunction with bar joists for supporting conduits or the like from the bar joists, and more particularly to a bar hanger which can be readily disposed on the top of a pair of chords of a bar joist used for supporting the roof, decking or ceiling in a building, the bar hanger being positioned rapidly without the use of tools for supporting the various hanging elements which carry such conduits.
In building structures bar joists spanning columns or the like are utilized for supporting various structures such as decking which carry the roof or ceiling. These bar joists in most buildings comprise a pair of angle beams, known as chords, spaced slightly apart and disposed so that one leg of each beam faces a corresponding leg of the other beam. Additional support to the bar joists are provided by a truss type of brace arrangement fastened to and between the angle beams and to another pair of chords at the bottom of the braces, the lower chords in many cases also being angle irons. Various conduits, such as sewer pipes, water pipes, electrical pipes and the like are supported and carried from the bar joist by means of a conduit hanger which cradles the conduit at the bottom thereof and is attached to the bar joist by means of clamps. These clamps generally have a C-shape configuration including a threaded member which attaches the clamp to one of the chords of the bar joist, and also includes a threaded socket for receiving a threaded rod which is attached to the conduit hanger. In other words, these clamps are similar to C-clamps connected to one of the chords and having a threaded receiver for receiving the threaded rod of the pipe hanging element.
Large buildings have a substantial number of such hangers and clamps, there generally being one approximately every ten feet for supporting fluid carrying pipes. For example, in a large shopping mall, where there are a substantial number of buildings or a single structure in which all the mall facilities are housed, there may be a few million of such hangers and clamps. Each of the clamps is a relatively inexpensive member, but the installation of the clamps can be quite time consuming and thus costly. In the aforesaid prior art clamps, the installation of each requires that each clamp be tightened on to the bar joist or chord flange, and then the threaded rod of the conduit hanger must be connected to the clamp. Wrenches or similar tools are required to secure the clamp to the bar joist. Moreover, because the clamp is connected to the flange of a single chord of the bar joist, a twisting or torsion results on that top flange so that the load carrying capacity of the bar joist is inefficient. Additionally, over a period of time, vibration in the building tends to loosen or cause the clamps to turn or slip, and sometimes these clamps loosen to the point that they slide off the flange resulting in water damage and the like to the building.